In many structures, such as office buildings, apartments, and the like, panel assemblies are used to provide a cosmetic ceiling between the actual ceiling and the occupied portion of the structure. Individual panel units, that form these assemblies, provide an aesthetically pleasing covering over service lines, such as ventilating ducts and electrical lines, and the unfinished actual ceiling. These panels can be secured in place by nails, screws or other fasteners that hold the panels to overhead frame members. Alternatively, each panel may be provided with clips that are snap-fitted to the grid members or cross tees that are suspended from the ceiling.
When the panels are being secured to the overhead frame members, they must be properly aligned or the final appearance of the ceiling will suffer. During instillation, it is difficult hold a panel steady so that it is properly positioned relative to the adjacent panels. This is in part because the panels are located above the heads of the workers performing the installation so as to put the panels in an awkward position to hold. Also, the act of driving a fastener through the panel and complementary frame member vibrates the panel so as to cause it to shift position. Consequently, the process of holding a panel steady while it is being installed is a bothersome task that takes some skill and patience to perform.
Moreover, in many panel assemblies, the individual panel units are disconnected from each other and maintained in assembly only by the supporting structure. Consequently, the panels are unable to support each other in the event the panels are struck or exposed to excessive vibrations. The former situation can occur in many environments where the panels are used when individuals inadvertently strike a panel with an object such as a ladder or a ball. A panel might also shift position because of the normal vibrations of the service lines located near the panel or as a result of the normal vibrations of the overlying actual ceiling, which often functions as a floor for another level of the structure. Panel vibrations are also a problem for structures located in earthquake zones. Regardless of the cause, once a panel unit starts to move, it can work free of the supporting structure to which it is attached. Once that occurs, the panel will fall to the floor and have to be refitted in place. This may involve removing and reinserting a number of panels so that they will appear uniformly fitted together. Moreover, when a panel falls from the ceiling, there is a likelihood that any persons standing underneath will be struck and injured.